Browsing Marine Resource Series by Title
Now showing items 21-24 of 24
A Socio-economic Study of Fisheries in Counties Cork, Donegal, Kerry and Galway(Marine Institute, 2000)Ireland has an extensive continental shelf within its 200-mile Economic Zone and has contributed enormously to EU Common Fishery Resources. Irish access to these fisheries was decided under previous fishery agreements and it is felt that Irish coastal communities have been seriously disadvantaged under EU fishery policy. This report hopes to advance arguments that will persuade the EU that Irish fishing communities should have a more equitable share of contiguous fish stocks under the 2002 review of the CFP. Project No. 97.IR.MR.008 was undertaken by The Institute of Technology, Tralee and Aqua-Fact International Services Limited (Galway) to provide a Socio- Economic Evaluation of the impact of fisheries and aquaculture in Counties Donegal, Galway, Kerry and Cork. This report deals with sea fisheries. It covers Counties Donegal and Kerry in their entirety, County Galway excluding Galway City and the Coastal Rural and Urban Districts of County Cork. These districts of County Cork comprise the Rural Districts of Bandon, Bantry, Castletownbere, Clonakilty, Dunmanway, Kinsale, Midleton, Skibereen, Schull and Youghal No.1 and the Urban Districts of Clonakilty, Cobh, Kinsale, Midleton, Skibereen and Youghal. Galway City is included in the maps, not in the tables, figures or appendices. The study of aquaculture is published separately. The two studies share the secondary socio-economic data and complement each other.
Strain selection in the edible brown seaweed Alaria esculenta: Genetic fingerprinting and hybridization studies under laboratory conditions(Marine Institute, 2000)The genus Alaria presently includes 12 species, 11 of which are located in the cold temperate North Pacific and only one is found in the North Atlantic (Widdowson, 1971). The North Atlantic species Alaria esculenta has two northern forms, A. esculenta forma grandifolia and forma pylaii (Lüning, 1990). The study presented here will concentrate on the genetic fingerprinting of Alaria esculenta, the most common North Atlantic species, and hybridisation of members of the Laminariaceae.
A Study of Selected Maërl Beds in Irish Waters and their Potential for Sustainable Extraction(Marine Institute, 2000)Although maërl beds are both of economic importance and conservation interest, data on the distribution of beds and their associated communities are lacking in Irish waters. This report describes the spatial distribution and volume of the maërl resource (Lithothamnion corallioides, Phymatolithon calcareum) along the west coast of Ireland from Donegal to Cork. Taking an average thickness of 2m (range: 0.1 – 3m) the current study estimates that the total national exploitable maërl bearing resource is of the order of 3 x 10^6 metres cubed. The Report outlines guidelines for the exploitation of this natural resource, which because of its extremely low growth rate, cannot be considered a renewable resource in the strictest sense.
A Survey of Bottlenose Dolphins (Tursiops truncatus) in the Shannon Estuary(Marine Institute, 2000)The bottlenose dolphin Tursiops truncatus is a ubiquitous species found throughout the temperate and tropical oceans of the world. The bottlenose dolphin population that occurs in the Shannon is one of only six known resident European populations. Since 1994, a small dolphin watching industry has been operating in the estuary, with plans for expansion. The objectives of this were to a) assess the degree of residency of bottlenose dolphins in the Shannon; b) estimate the population size and assess the production of calves; c) examine the social structure of the population; d) study habitat use and e) examine the effects of boats on dolphin behaviour. Boat-based surveys and photo-identification techniques were used to derive a population estimate and to examine distribution and movements of individually identifiable dolphins over a two-year period. Land-based scan samples were used to examine behavioural activity and interactions of dolphins with all categories of boat traffic. Trips on dolphin watching boats examined whether these boats were interacting with the same individual dolphins on a trip, daily or weekly basis. Dolphins were recorded in all months of the year but with a seasonal peak between May and September. Many of the identifiable dolphins were resighted throughout the study indicating a high degree of residency. Using photo-identification and mark-recapture analyses, the population estimate for the Shannon is 113 dolphins (CV 0.14, 95% C.I. 94 - 161). The presence of neonatal calves only from July – September indicates that there is a marked breeding season for this population and that the area is important as a nursery area. Group sizes ranged from singletons to groups of 32 animals and while dolphins were seen throughout the study area, groups were frequently encountered in the narrow water at Kilcredaun and in the mouth of the estuary. A second area of concentrated sightings was identified further up-river around Moneypoint and Tarbert/Killimer. This group comprised a smaller number of individuals, and the re-encounter rate of these individuals in the same area suggests a degree of habitat partitioning. These dolphins may be more vulnerable to dolphin watching activities than the more diffuse numbers in the outer estuary. The influence of tidal cycle was recorded at Kilcredaun and at Killimer/Tarbert with a distinct peak in sightings in the four-hour period before low tide. The frequency distribution of association indices shows that there are few "strong" associations between individuals and supports the notion of a fluid and gregarious social structure. Dolphin watching boats were involved in 61.8% of all interactions with dolphin groups, higher than any other category of boat. At present, two operators make approximately 200 dolphin watching trips annually, carrying a total of 2,400 passengers per year. The operators are highly successful in locating dolphins (97%) and the tour boats rarely come into contact with each other on the water and generally search in different areas and watch different groups. The potential for land-based dolphin watching was examined and possible sites identified. The information from this study provides a basis from which sound conservation management strategies can be developed, in order to properly conserve the species and its habitat, to develop a sustainable dolphin watching industry and to develop/monitor other coastal zone industries such as oil and gas exploration and shipping development within the Shannon.